The patent filing from California-based OpenTV will cause waves at Amazon because it predates its own 1-Click patent - which it is currently scrapping over with Barnes & Noble - by three years.

Thanks to this early filing date and the publication of the European equivalent patent application, "Amazon could be precluded from using its patent against anyone practicing what is taught in our patent," said Opperman.

Last October Amazon decided to sue Barnes & Noble over allegedly copying the 1-Click invention - to which Amazon won the patent on September 28. Although it did win a preliminary injunction against Barnes & Noble, the spat is still raging.

Apple recently became the first company to license the 1-Click technology from Amazon to use on its Apple Store. ®